Re: HSC Chemistry Marathon 2017

At this rate you aren't gonna finish the whole course in these 2 week holidays rip

Just finished my POM notes but will need to spend a lot of time reediting and perfecting it lmao

Same with phys but I'm only halfway there for space.

Question:
Describe how ONE named biopolymer is made AND explain its usefulness in term of it properties. (5 MARKS) (trecex, please don't avoid this question no matter how easy you think it is because if you skip it, you ruin the purpose of the marathon)

Re: HSC Chemistry Marathon 2017

Originally Posted by eyeseeyou

No he said "the biopolymer question isn't really hard" hence he skipped it

It really isn't, that whole dotpoint is 100% memorising, defeats the purpose when you have access to wikipedia (you can look it up yourself PLA/PHB).
Someone who doesn't do chemistry could answer it just by copying out the information there.

Re: HSC Chemistry Marathon 2017

Originally Posted by eyeseeyou

Just finished my POM notes but will need to spend a lot of time reediting and perfecting it lmao

Same with phys but I'm only halfway there for space.

Question:
Describe how ONE named biopolymer is made AND explain its usefulness in term of it properties. (5 MARKS) (trecex, please don't avoid this question no matter how easy you think it is because if you skip it, you ruin the purpose of the marathon)

Well if you can't answer the question it's a sign that you should edit your notes for that specific syllabus point

Re: HSC Chemistry Marathon 2017

Originally Posted by trecex1

It really isn't, that whole dotpoint is 100% memorising, defeats the purpose when you have access to wikipedia (you can look it up yourself PLA/PHB).
Someone who doesn't do chemistry could answer it just by copying out the information there.

It doesn't matter, just answer it so then we can run the marathon smoothly again

Re: HSC Chemistry Marathon 2017

Originally Posted by eyeseeyou

It doesn't matter, just answer it so then we can run the marathon smoothly again

Polylactic Acid (PLA) is different than most thermoplastic polymers in that it is derived from renewable resources like corn starch or sugar cane. Most plastics, by contrast, are derived from the distillation and polymerization of nonrenewable petroleum reserves. Plastics that are derived from biomass (e.g. PLA) are known as “bioplastics.”

Polylactic Acid is biodegradable and has characteristics similar to polypropylene (PP), polyethylene (PE), or polystyrene (PS). It can be produced from already existing manufacturing equipment (those designed and originally used for petrochemical industry plastics). This makes it relatively cost efficient to produce. Accordingly, PLA has the second largest production volume of any bioplastic (the most common typically cited as thermoplastic starch).

There are a vast array of applications for Polylactic Acid. Some of the most common uses include plastic films, bottles, and biodegradable medical devices (e.g. screws, pins, rods, and plates that are expected to biodegrade within 6-12 months). For more on medical device prototypes (both biodegradable and permanent) read here. PLA constricts under heat and is thereby suitable for use as a shrink wrap material. Additionally, the ease with which Polylactic Acid melts allows for some interesting applications in 3D printing (namely “lost PLA casting” - read more below). On the other hand, its low glass transition temperature makes many types of PLA (for example, plastic cups) unsuitable to hold hot liquid.

Re: HSC Chemistry Marathon 2017

Originally Posted by trecex1

New question (5 marks)

The following extract was taken from a blog about environmental issues."...the use of long-lasting for short lived applications can cause problems for the preservation of living systems..Plastic debris has a costly impact on waste management for municipalities."

Assess the use of polystyrene and a named biopolymer in terms of their properties, with references to the statements made in this blog.

The following extract was taken from a blog about environmental issues."...the use of long-lasting for short lived applications can cause problems for the preservation of living systems..Plastic debris has a costly impact on waste management for municipalities."

Assess the use of polystyrene and a named biopolymer in terms of their properties, with references to the statements made in this blog.

The uses associated with polystyrene for airblown things such as eskies and styrofoam cups. Also can be used for transparent CD case and plastic transparent cups

One biopolymer is biopol. Biopol is a PHB/PHV blend. it has properties similar to polypropylene and has been used to make non-toxic and decomposable sutures in medicine as it was used in shampoo bottles but had to be abandoned due to the cost

Some of the properties of PHA biodegradable as it can used for recyling of objects such as nappies and kitchen firm, biocompatible as it is used for a surgical thread and other medical applications and it is suitable to replace polypropylene for many applications

The issue regarding this is production of biopol is expensive and research is required to increase efficiency and reduce costs

Hence, it causes problems as it has a costly impact on waste management for municipalities

Question: Identify ONE radioisotope used in the fields of medicine AND industry and explain their use in terms of properties. (6 MARKS)

By the way, someone needs to answer my G-force question in the physics marathon

Also is anyone here up to acidic environment or chemical management and monitoring?

Re: HSC Chemistry Marathon 2017

Originally Posted by eyeseeyou

The uses associated with polystyrene for airblown things such as eskies and styrofoam cups. Also can be used for transparent CD case and plastic transparent cups

One biopolymer is biopol. Biopol is a PHB/PHV blend. it has properties similar to polypropylene and has been used to make non-toxic and decomposable sutures in medicine as it was used in shampoo bottles but had to be abandoned due to the cost

Some of the properties of PHA biodegradable as it can used for recyling of objects such as nappies and kitchen firm, biocompatible as it is used for a surgical thread and other medical applications and it is suitable to replace polypropylene for many applications

The issue regarding this is production of biopol is expensive and research is required to increase efficiency and reduce costs

Hence, it causes problems as it has a costly impact on waste management for municipalities

Question: Identify ONE radioisotope used in the fields of medicine AND industry and explain their use in terms of properties. (6 MARKS)

By the way, someone needs to answer my G-force question in the physics marathon

Also is anyone here up to acidic environment or chemical management and monitoring?

You would get 2/5, maybe 3 if the markers were very generous.
You didn't make any reference to the extract except restating it, also your assessment completely contradicts the information you gave.

Re: HSC Chemistry Marathon 2017

Originally Posted by eyeseeyou

The uses associated with polystyrene for airblown things such as eskies and styrofoam cups. Also can be used for transparent CD case and plastic transparent cups

One biopolymer is biopol. Biopol is a PHB/PHV blend. it has properties similar to polypropylene and has been used to make non-toxic and decomposable sutures in medicine as it was used in shampoo bottles but had to be abandoned due to the cost

Some of the properties of PHA biodegradable as it can used for recyling of objects such as nappies and kitchen firm, biocompatible as it is used for a surgical thread and other medical applications and it is suitable to replace polypropylene for many applications

The issue regarding this is production of biopol is expensive and research is required to increase efficiency and reduce costs

Hence, it causes problems as it has a costly impact on waste management for municipalities

Question: Identify ONE radioisotope used in the fields of medicine AND industry and explain their use in terms of properties. (6 MARKS)

By the way, someone needs to answer my G-force question in the physics marathon

Also is anyone here up to acidic environment or chemical management and monitoring?

The g-force question is literally a syllabus dot point so yeah. Also this response as trecex said isn't that good, has no grammar and no effort put into it which is unfair for the people that answer your questions with effort

Re: HSC Chemistry Marathon 2017

Hey guys,

So we pretty much just started the HSC course for Chemistry. Now, this is a probably a stupid question but... is everything I learn from now on completely necessary for the HSC? Because I know that for some subjects it isn't and obviously not all of the prelim stuff in Chemistry comes into play in the HSC course. I just need a sort of re-assurance and a forceful nudge to let me know that I NEED TO STOP EFFING AROUND and get to work. Same goes for physics. If anyone can give me an insight I'd appreciate it. Also, I just realised how small the syllabus and the dot points for each module are - IT ALL LOOKS SO NICE AND KIND AND EASY. With that being said, I should probably get to work.

Re: HSC Chemistry Marathon 2017

Originally Posted by dragon658

Hey guys,

So we pretty much just started the HSC course for Chemistry. Now, this is a probably a stupid question but... is everything I learn from now on completely necessary for the HSC? Because I know that for some subjects it isn't and obviously not all of the prelim stuff in Chemistry comes into play in the HSC course. I just need a sort of re-assurance and a forceful nudge to let me know that I NEED TO STOP EFFING AROUND and get to work. Same goes for physics. If anyone can give me an insight I'd appreciate it. Also, I just realised how small the syllabus and the dot points for each module are - IT ALL LOOKS SO NICE AND KIND AND EASY. With that being said, I should probably get to work.

Re: HSC Chemistry Marathon 2017

Originally Posted by eyeseeyou

please refrain from derailing this thread. If you want to talk about a specific topic or whatever to someone else, please do it via PM or have the conversation somewhere else as we want the marathon running smoothly[/COLOR][/B]

Re: HSC Chemistry Marathon 2017

I posted this in the outdated 2k16 thread by accident (-.-'') but what does this mean? I'm really confused by the 'one less/more oxygen than they normally bond to' part.

-ide - elements that react without oxygen
-ite - Elements that reacted with one less oxygen than they normally bond to
-ate - Elements that reacted with the number of oxygen molecules that they normally bond to
-per/ate-Elements that reacted with one additional oxygen molecule than they normally bond to

Re: HSC Chemistry Marathon 2017

Originally Posted by trecex1

Polylactic acid (PLA) is a thermoplastic polymer that is is derived from renewable resources like corn starch and sugar cane. Most plastics are polymers of nonrenewable petroleum reserves. Plastics derived from biomass (e.g. PLA) are known as “bioplastics”.

PLA is biodegradable and has similar properties to polypropylene (PP), polyethylene (PE), or polystyrene (PS), and its production is compatible with existing industrial equipment used for traditional polymer synthesis. This makes PLA production relatively cost efficient. Accordingly, PLA is the second highest bioplastic produced by volume, only behind thermoplastic starch.

Uses of PLA include plastic films, bottles, and biodegradable medical devices (e.g. screws, pins, rods, and plates that are expected to biodegrade within 6-12 months). For more on medical device prototypes (both biodegradable and permanent) read here. PLA constricts under heat, making it suitable for use as a shrink wrap material. Additionally, the ease with which PLA melts allows for some interesting applications in 3D printing (namely “lost PLA casting” - read more below). In contrast, its low glass transition temperature (include a temperature?) limits its use at high temperature due to deformation.

I have made some changes so you can see what it might look more like (not complete, but still).

A few points:
1. A lot of changes to be made here, you can definitely improve your writing skills. You need to think about using less words to convey the same information - you use a lot of hand-wavy phrases and have a lot of fluff that adds nothing to your argument. Furthermore, long linking phrases like "on the other hand" make writing more convoluted.
2. If you create an acronym - USE IT.
3. Names of chemicals should not be capitalised unless it is at the start of a sentence. This means "acid" should never be capitalised.
4. Avoid vague phrases like "hot liquid" - try to specify a temperature range. What temperature does PLA become malleable and thus, preventing it from holding liquids at that temp. Another phrase I don't like is "screws, pins, rods, and plates" - are these implants? If so, just say medical implants.
5. Avoid using brackets as much as you can - you really shouldn't ever need full sentences in brackets. It's good to keep it to five words or less within brackets.